The headquarters of the U.S. Food and Drug Administration (FDA) is shown in Silver Spring, Maryland.
The headquarters of the U.S. Food and Drug Administration (FDA) is shown in Silver Spring, Maryland. REUTERS

Medtronic Inc. (NYSE: MDT) said the U.S. Food and Drug Administration (FDA) approved its Revo MRI pacemaker - the first such device in the U.S. designed for safe use during certain magnetic resonance imaging (MRI) exams.

Pacemakers are surgically implanted medical devices that generate electrical impulses to treat irregular or stalled heart beats. MRIs use a powerful magnetic field, radio frequency pulses and an internal computer to produce detailed images of organs, soft tissues, bone, and other internal body structures not available with other imaging methods.

According to the FDA, about half of all patients with pacemakers may require an MRI, but are advised not to have one because an MRI’s magnetic and radiofrequency fields can disrupt the pacemaker’s setting or cause wires to overheat, resulting in unintended heart stimulation, device electrical failure, or tissue damage.

The U.S. health regulator said it reviewed results from one clinical trial of 484 patients. Of those, 464 were successfully implanted with the device and then randomized to receive or not receive an MRI. None of the 211 who underwent an MRI experienced an MRI-related complication.

Until now, MRI procedures were not recommended for patients with implanted pacemakers due to the potential for adverse events. Each year, an estimated 200,000 pacemaker patients in the United States have to forgo MRI scans each year.

Medtronic's Revo MRI SureScan Pacing System includes a function that is turned on before a scan to prepare patients for the MRI. The pacemaker’s use in MRIs is limited to certain patients, certain parts of the body, and certain scanning parameters.

Before the introduction of Revo MRI, pacemaker patients could face serious complications if they were exposed to the powerful magnetic fields generated by MRI machines, which can be as much as 30,000 times more powerful than the Earth’s magnetic field

Though the product received approval from the health regulator, a warning letter following inspection of the company's Medtronic's Mounds View, Minnesota, manufacturing facility remains in place.

“We are continuing to work with FDA toward a final resolution to the Mounds View warning letter and are optimistic that we are making progress toward this goal,” said Medtronic's senior vice president Pat Mackin.

The company said it will start shipping Revo MRI immediately.

Shares of Medtronic ended Tuesday's trading at $39.81.